Electrical control system



May 22, 1934. s. L. McFADlN 1,959,379

ELECTRICAL UNTROL SYSTEM Filed Sept. 5, 1929 5 Sheets-Sheet l :EJ l

B A IN VEN TOR.

May 22, 1934- s. L. MFAD|N 1,959,379

ELECTRICAL CONTROL SYSTEM Filed Sept. 3, 1929 5 Sheecs--Sheei'I 2 D. C.Power Circuit .Disk

Q/ D. C

T' A B Glo sed here 55 Closed, by movement of disk.

Opens A.. C@ circuit.

Key closed.

INVEN TOR.

BY Disk moves. JK" D. C. power and control closed ATTORN Y May 22, 1934.

ELECTRICAL CONTROL SYSTEM Filed Sept. 5, 1929A 5 Sheets-Sheet 3 Hagf- IClosed, @wwwa dem.

c11'cu1t /4 closed (I r f L Z5 l/Q/ rd f//J ,5 9 Spring' closes {0 9circuit I( T No A. c. trip circuit is re when trip Contact strikes, 1tcauses solenoid 66 [IJ-'E S to open contacts at 68.

\ V Disk stops, due to contacts open at 68 and 8,11 contacts return tonormal position.

,f Instant contact Power circuit \Com1non ///5 l Contact. INVENTOR.

fau/f 5;- Qlo 274014, A C.

BY Egg d TTORNEYV?.

May 22, 1934.

:En E

ELECTRICAL Filed sept. 3, 1929 MCFADIN CONTROL SYSTEM 5 Sheets-Shea?l 4closed by pressure MZ of disk. 6. .C.

Closed here and disk rebounds, which action v opens the circuit.

prevent too sudden stoppage of disk.

This circuit opens controlci rcuit to while Kot)l is closed.

Opened by pressure of disk. Disk rebounds, thus closing circuit forfuture use.

Opened, while current is `ln solenoidcircuit, thusv insuring opencircuit on opposite side.

IN VEN TOR.

Common Disk has reversed and. stoppecl.

TTORNEY May 22, 1934. s. l.. MCFADIN ELECTRICAL CONTROL SYSTEM FiledSept. 5, 1929 5 Sheets-Sheet 5 l; iE-

bolo ooe jul :il l :c1 L-- IN VEN TOR.

' inf Patented May 22, 1934 UNITED STATES PATENT OFFICE ELECTRICALCONTROL SYSTEM Application September 3,

3 Claims.

My invention relates broadly to control apparatus and more particularlyto an apparatus for the control of electrical circuits at distant pointsby electr-ical energy.

One of the objects of my invention is to provide an electrical controlapparatus, whereby a multiplicity of separate circuits may beselectively controlled in step-bystep operation-s, the control apparatusbeing brought to a selected position depending upon the character of thecontrol signals.

Another object of my invention is to provide a construction of circuitselecting apparatus which may be controlled by signals transmitted froma distance for closing predetermined circuits successively instep-by-step order and restoring all of the circuits substantiallysimultaneously to their original condition.

Still another object of my invention is to provide a construction ofcontrol apparatus having a rotary actuator which may be rotated throughpredetermined angular distances to shift a plurality of disc membersinto selected positions fors closing electrical circuits upon thereceipt of predetermined control signals.

A further object of my invention is to provide a construction of controlapparatus in which a reversible motor may be actuated by a controlsignal to rotate a contact carrying disc to selected positions forclosing a multiplicity of control circuits upon receipt of particularpredetermined control signals.

A still further object of my invention is to provide a construction ofcontrol apparatus employing relay devices for actuating a control uponreceipt of a control signal with minimum inertia, the relays functioningunder the combined influence of direct and alternating current utilizedin the control system.

Other and further objects of my invention reside in the construction ofcontrol apparatus and circuit arrangement as more fully hereinafterdescribed and as illustrated in the accompanying drawings, in which:

Figure 1 diagrammatically illustrates the control apparatus embodyingthe principles of my invention; Fig. 2 is a simplified wiring diagramshowing the direct current power circuit employed in the system of myinvention; Fig. 3 illustrates the direct current power and controlcircuit in closed position; Fig. 4 illustrates the condition of thecircuits in the next succeeding step after the position illustrated inFig. 3; Fig. 5 illustrates the circuit which is employed to positivelyopen the contacts of the main control relay in the 1929, Serial No.390,147

(Cl. F- 375) power circuit; Fig. 6 illustrates the positive meansemployed to close the reverse circuit though the power control relay atthe end of the path of travel of the contact device in the selectorapparatus; Fig. '7 shows the position of the control 60 relays when theselector disc has returned to its initial position after reversemovement from the position shown in Fig. 6; and Fig. 8 illustrates onesystem of circuits on the landing field of an aircraft system, whichcircuits are selectively controlled by the apparatus illustrated inFigs. l and '7.

The control apparatus of my invention may be actuated by signalstransmitted from aircraft approaching a landing field to selectivelyclose circuits on the landing field for indicating to the approachingaircraft the safety limits for the landing of the aircraft and otherwisedenote the character and geographical location of the landing field.While the control apparatus of my invention is adapted for actuation bysignals transmitted by radiant energy the control circuits may beactuated by signals transmitted by line wire in other systems ofcontrol. In describing my invention in connection with a remote controlsystem of radio transmission I do not intend to limit my invention toradiant energy control, and it is desired that it be understood that thecontrol system of my invention may be actuated either by line wire or 35by radio for performing the functions of successively closing electricalcircuits in predetermined order and thereafter restoring the circuits totheir original condition preparatory to the reception of a furtherseries of control impulses.

When the apparatus of my invention is used as a responsive system toradio signaling energy I locate the apparatus on a control panel whichis mounted with respect to the control apparatus in such manner thataccess may be had to the several relays and parts of the equipment foradjustment and repair and replacement of parts. The control apparatusmay be located in the radio receiving station adjacent the landing fieldof an aircraft landing station.

I have illustrated in Fig. 8 one arrangement of the control system inwhich the receiving apparatus is located adjacent the aircraft landingiield and control signals received from aircraft on the radio antennaeillustrated for the operation of a relay system at the receiver and theactuation of the control apparatus of my invention for successivelyopening or closing the circuits to the aircraft landing eld.

The control panel of my invention shown in by engagement of theprotruding members on the Fig. 1 includes an automatic switchingmechanism which is driven under control of an alternating current motor.I have represented the several parts of the apparatus on the controlpanel diagrammatically including the reversible series connected Amotor36 having opposed poles 31 and 32 on opposite sides of rotatablearmature 33. The opposed poles are wound with separate windings which Ihave designated at 34, 34a, 35Vand 35a. The windings are independentlyenergized to effect rotation of the motor in dierent directions. Themeans which I provide for controlling the direction of rotation of themotor will be described in detail. A suitable source of direct currentenergy is utilized at the receiving station, such as the lightingcircuit direct current supply or a storage battery source of 6 to 12volts.

In order to render the system of my invention permanent in itscharacter, I prefer to employ a direct current lighting circuit,although I may employ any suitable storage battery source, such as a gasengine driven generator, with floating battery system connected theretofor supplying the motor of the control apparatus of my invention. I haveindicated the direct current source by reference character 36. The motorhas its shaft suitably geared to revolve a turntable that I haveindicated at 37, which turntable carries a multiplicity of contactmembers which will be more fully described hereinafter. Ihave indicatedthe connecting shaft Vgenerally at 58 including clutch members 59 and 60suitably spring pressed at 61 so that motor 30 may revolve disc 37 to apoint where an obstruction is reached disc 37 with a switch locatedadjacent the disc, as will be more fully hereinafter described. At thetime of abutment between the members carried by disc 37 with the switchadjacent disc 37 there will be suicient slippage between the motor driveshaft and the drive to the disc 37 as will prevent any injury to theparts of the driving mechanism.

The central portion of the turntable 37 is shown at 38 carrying amultiplicity of contacts spaced one from the other disposed at 1c, 2c,3c, 4c, 5c, 6c and '7c adjacent the peripheral edge of the disc 38.4Adjacent the opposite peripheral edge of the disc 38 I provide acontinuous contact strip 40 over which brush vmember 41 may sweep. Inthe normal position of the disc 38 brush 41 is out of Contact with strip40, as will be noted from the gap 42 between the end of strip 40 andbrush members 41. The Contact members lc, 2c, 3c, 4c, 5c, 6c and 7c areso spaced from each other that brush 43 successively contacts with eachof the contact members 1c, 2c, 3c, 4c, 5c, 6c and 7c and passes overinsulation material on the peripheral edge of disc 38 intermediate eachof the contacts 1c, 2c, 3c, 4c, 5c, 6c and 7c. The contactmembers areelectrically connected as shown, and connected with the additionalcontact member 8c through wire 117 and connected to the continuouscontact strip through wire 117a, which is varranged to establish wipingcontact with brush member 45 at the time that brush member 43 is clearof the last contact'7c of the set of contact members lo, 2c, 3c, 4c, 5c,6c and 7c on member 38. The disc 37 carries a multiplicity of contactsadjacent the peripheral edges thereof which I have shown at la, 2a, 3a,4a, 5a, 6a and 7a. The contacts 46 are spaced one from the otheradjacent the peripheral edge of disc member 38 to allow successivecontact to be made with brush `tongues 63 and 64. I provide a Contactmember 47 as the disc is moved by motor 30. The brush member 47 ispivoted at 48 and is spring pressed on each side thereof as representedat 49 for insuring a quick snap action as the brush 47 wipes eachContact 46 successively. The sets of contacts ltr-7a and 1c-8a arearranged in separate control circuits for completing selected circuitsunder step by step movement of the switching apparatus. v

The contact members 46 are electrically connected in parallel and areconnected to the strip 50. The disc 37 carries strip member 50 adjacentthe peripheral edge thereof, as shown, which strip may establish contactwith a multiplicity of separate brushes which I have designated at 1, 2,3, 4, 5, 6, 7 and 8 in addition to a common brush shown at 10. I haveshown eight brushes. This number may be varied in accordance .with thenumber of circuits which are to be controlled by the system of myinvention. I provide an independent brush 51 in sliding f engagementwith continuous strip forv the control of the motor circuit, as will bedescribed hereinafter.

The rotary disc 37 also carries a mechanical breaker 52, which isdisposed at an acute angle with respect to the line of theopposite'mechanical breaker which I have shown at 53. These mechanicalbreakers 52 and 53 serve to actua-teV a switch device which I havedesignated generally at 54 mounted on the panel adjacent the rotarydisc. The rotary disc 37 also carries a bridging strip 55 which isadapted to shunt a pair of brushes designated at 56 when the disc 37moves to a position Where contact strip 55 bridges the brushes 56.

In order to provide for the braking of the motor 37, I provide asolenoid 57 which operates a brake shoe 62 engaging the peripheral edgeof disc 37 for bringing the disc-37 to a stop immediately upon thecompletion of the circuit which connects to solenoid 57. The switchdevice 54 comprises two independent sections, one sectionl of whichincludes the movable tongue 63` and the.

other section of which includes the movable tongue 64. Tongue 63 ispivotally mounted at 63a and extends rearwardly from the pivotedmounting to a position where it connects with the moving member 65 of asolenoid 66 by which the tongue 63 may be moved into contact with thecontact strip 67 and away from contact strip 68. The tongue 64 ispivotally mounted at 64a and has a rearward extension 69 thereon bywhich tongue 64 may be moved under control of solenoid 70 out of contactwith contact strip 7l. 'I'he central member 72 is permanently anchoredt0 the control panel and is electrically connected through lead 73 withmagnet windings 74, as will be more fully described hereinafter. Themember 72 forms a mechanical stop for each of the spring 63h on tongue63, which may establish electrical connection with stop 72 while aninsulation member 64b is carried by tongue 64,V which preventsconnection between tongue 64 and stop 72. Each of thetongues 63 and 64have extensions 63e and 64o thereon by which the tongues may be moved byabutment of mechanical breakers 52 and 53 with the protruding portions63e and 64e of tongues 63 and 64.

I provide a relay 93 having relay windings 74, the relay being of thedouble action type, in which opposed windings a moving armature 76disposed therebetween with sides thereof. When windings 74 are energized75 are provided with` armature 76 will be drawn upwardly, and whenwindings are energized armature 76 will be drawn downwardly closing thecircuit between armature 76 and contact 78. The direct current supplycircuit extends from the source 36 through conductor 79 to the midwaypoint 80. In the condition of the circuit as illustrated the directcurrent passes along conductor 81 through electromagnet 82 of relay 83,thence through relay winding 84 of relay 85 to contact 86 which maycomplete connection with a contact carried by armature 87 to completethe direct current circuit through conductor 88, windings 75 and movingarmature, and contact system 89 of relay 90, thence to tongue 68 andtongue 63 of switch 64 to conductor 91, returning to the direct currentsource 36. The tongue 63 is normally in contact with tongue 68 by virtueof the leaf spring assembly shown at 92. The direct current circuit astraced is ineffective until the tongues of several relays 83, and 93 areactuated.

The alternating current supply circuit receives energy from a sourcedesignated at and energy is carried over conductor 96 to the brush 97 ofthe driving motor 30, thence through the armature winding 98 to brush99, and through the eld windings 35a and 35 to the moving armature ofrelay 83 winding 100 to conductor 101, which is the opposite side of thealternating current supply circuit when the contacts of the relay 83 areclosed. The solenoid winding 100 is so proportioned with respect tosolenoid winding 82 that by the combined electromagnetic effects ofthese windings the armature of the relay 83 is maintained in closedposition even under conditions of shock vibration to which the apparatusmay be subjected, but upon failure of current in either winding 82 orwinding 100 after the initial closing of the circuit through contacts100e, armature 83 is drawn away from the stationary contact of the relayby the action of spring 83a.

It will be noted that in supplying the alterhating current energy to themotor circuit the relay 83 is not self-actuating. That is, the contactsbetween the moving armature and the stationary contact of relay 83 arenormally open and the relay must be preconditioned. Until solenoid 82 isenergized by direct current, the alternating current will not besupplied to the motor circuit. Relay 83 serves as a circuit breaker, forwhen the relay is closed, the alternating current passing throughsolenoid winding 100 aids and assists in maintaining the relay contactsclosed, but upon failure of direct current in winding 82, the relayopens under action of spring 83a. In order that the circuit to the motormay be closed, a signal must be impressed upon the control through relaycontacts which are controlled by the keying circuit 102. The energy,which is made effective upon the receipt of a signal, o1' upon theoperation of a keying circuit at the position shown at 102, is conveyedthrough conductor 103 and through winding 104 of the double actingsolenoid relay 105 having sets of opposed contacts 106 vand 107 whichconnect in the alternating current circuits, which will be hereinafterdescribed. The signaling control circuit continues through conductor 108through winding 109 of the relay system 110 and then through winding 111of relay 85. The opposite end of the solenoid winding 111 connects toarmature 87 which is in common with the conductor 88 of the directcurrent circuit, which conductor is utilized to lead the signal controlcircuit to the side B of direct current source 36.

The return circuit may be traced through conductor 88, winding 75, relaycontacts 89, tongues 68 and 63 of switch 64 and conductor 91 to the Bterminal of the direct current source 36. The A terminal of directcurrent source 36 connects to the opposite side of signal controlcircuit 102. Upon energizing solenoid 111 the armature 87 of relay 85 isdrawn downwardly to close contact 86, effectively energizing solenoid 84in the direct current circuit and energizing relay winding 82 of relay83, thereby closing the alternating current circuit to the motor 30 andcausing the motor to revolve and correspondingly rotate discs 37 and 38.

The effect of energizing winding 109 of relay is the opening of contacts112 and the separation of contacts 113, thereby preventing closing ofcontacts 113 even though solenoid 114 may be energized. Contacts 113 arenormally maintained in open position and when solenoid 109 is energizedthese contacts are so widely separated that energiza'tion of solenoid114 at that time will not be effective to close contacts 113. It followsthat solenoid 109 must be deenergized before contacts 113 can be closedunder the influence of solenoid 114. This arrangement of relay contactshas been found to be a feature of safety to pre- Vent interference withthe controls at undesired time periods. The circuit through contacts 112extends from conductor 115 which is connected to the side B of thedirect current source 36 through the circuit including relay windings75, relay contacts 89 and tongues 68 and 63 of switch 64. The circuitthrough contacts 112 extends through conductor 116 to brush 41, wherebysliding connection is established with contact strip 40 as the discs 37and 38 are advanced. The circuit extends frorn contact strip 40 throughbridging conductor 117 on disc 38, which connects to the contact members39. The circuit also extends through shunting conductor 117a to contact40 carrie-d by disc 38. The circuit is completed. by wiping contactbetween contact members le, 2c, 3c, 4c, 5c, 6c and 7c, etc., with brush43, which connects through lead 118 to the solenoid winding 114 of relay110. The circuit continues through conductor 119 to contact 78 of relay93 and through tongue 76 to conductor 120 where it leads to the Aterminal oi the direct current source 36. The circuit just described isonly completed when windings 75 are energized from the direct currentsource and at the time that contact strips 63 and 68 are closed withrespect to each other and at the time that the relay contacts 89 areclosed.

When the keying or relay control circuit 102 is closed and the discs 37and 38 are being revolved contact 113 is held open, but upon releasingthe keying or relay control circuit 102 solenoid 114 becomes effective,by virtue of the closed path from the source through winding 114,conductor 118, brush 43, selected ones of contact members 39, shuntingconductor 117, strip 40, brush 41, conductor 116 and contacts 112 to theopposite side of the direct current source through conductor 115.Contacts 113 are thus closed creating a circuit through wire 121 to thebrush 47, which establishes contact with a selected one of the contactmembers 46 on the disc 37, thus connecting through strip 50 and brush 10to one side of the alternating current source 95 at line energizingsolenoid 66 which moves armature 65 Yz' l im to a position which breaksthe circuitY between tongue 63 and tongue 68, thereby deenergizingelectromagnet winding V34 of relay 85releasing tongue 87, openingcontacts 86, deenergizing electromagnetic winding 82 and opening thealternating current supply circuit to the motor 30, thereby bringing themotor to a stop. It will be observed that the several sets of contactscorrespon-d on the several discs, that is contacts l, 2, 3, 4, 5, 6, 7and 3 correspond to the similarly numbered contacts having subscripts aand c. Correspondingcircuits which are selected simultaneously with theselection of the circuit through contact 1 may also be traced throughthe circuits terminating at contacts 1u and 1c, as will be hereinafterdescribed.

By timing the rotation of discs 37 and 38 contacts can be closed to thebrushes 1, 2, 3, 4, 5, 6, 7 and 8 successively to control differentcircuits connected to these contacts, an-d depending upon the timeperiod through which the motor 30 is operated the disc will advance tothe different circuit positions and may be brought to rest at anyselected circuit positon if the control circuit is deenergized after thediscs have advanced to the selected position. When the disc 37 hasadvanced to the full limit oi?A rotation permitted by abutment ofmechanical breaker 52 with the extension 631; of tongue 63, the circuitbetween tongue 63 and tongue 68 is broken and a circuit completedthrough spring member 63D, contact 72, through lead 73, through solenoidwinding 74 and conductor 120, thus insuring a quick break of the directcurrent circuit to the motor control by the withdrawal of armature 76from contact 7S; The opening of the contact between armature 76 andContact 78 deenergizes solenoid winding 114, opening contacts 113,deenergizing solenoid winding 66.

When disc 37 advances to a position where contact member 55 reaches thebrushes 56 a circuit is completed through contact member 5 through stripand contact brush 10 to the side 122 of the alternating supply line. Thealternating current passes from contact brush 56 through contacts 106or" relay 104 through the'conductor 130 to the control lead numbered 5which extends to the landing eld and connects to driving motor 132 ofthe revolving .beacons 133. So long as member remains on contacts 56,motor 132 rotates and beacon lights 133 sweep-the landing eld. Thisaction continues so long as the keying circuit 102 is open, for when thekeying circuit 102 is closed solenoid 104 is energized and contacts 106are opened thereby opening the circuit to the driving motor 132.

In order to bring the motor 132 to a stop in any given selected positionthe signaling circuit 102 is closed, thus moving disc 37 to a positionwhere contact member 6 connects with strip 50. By reason of the advancedposition of disc 37 contact strip 55 has moved past contact 56, and sothe circuit to driving motor 132 is opened and this condition madeapparent by an indicator lamp 135 connected to circuit 6 on the eldwhich receives energy fromY the alternating current line 122 throughbrush 10, contact strip 50 and brush 6 to the indicator lamp 135,leading to the opposite side of the alternating current source. The disc37 is next advanced another step by again closing-the signaling circuit102 by which the disc may be advanced a step to a position where strip50 connects with brush 7 thereby energizing solenoid winding 57. Thesolenoid 57 projects a brake shoe 62 against the peripheral edge of disc37, thereby reducing the rotative momentum of.

disc 37 preparatoryV to a reverse movement thereof. Contacts 107 ofrelay 105 are normally closed and are openedlwhen the signaling circuitis closed so that the brake is ineiective whenthe signaling circuit isclosed.

The mechanical movement of tongue 63 under control of breaker 52 issuchthat connection is established Ywith tongue 67, which establishes aconnection from the side B or" the direct current source throughconductor 125, through winding 126 of relay 110, returning throughconductor 127 and conductor 103 to signal control circuit 102, returningto the A side of the direct current source 36. By energizingwinding'126contacts 112 are opened, thereby breaking the circuit fromthe direct current source through brush 41 contacts strip 40, theselected one of contact members 1c, 2c, 3c, 4c, 5c, 6c, 7c and 8c, brush43, winding 114, lead 119 to contact 78, the tongue 76, back to the Aside of the direct current source 36 through conductor 126. A brush 8 isprovided for completing the circuit to the auxiliary equipmentV providedon the landing eld.

In order to reverse the movement of the disc 37 the energy must besupplied to the driving motor 30 through iield windings 34a and 34 in adifferent direction than supplied through eld windings 35a and 35. Thisis accomplished by means of relay systems, 136, 137 and138, as will bedescribed hereinater. When the disc 37 has reached the limit of itscounter-clockwise rotation connection is established between contact 8cand brush 45 by which energy is supplied from the side B of the directcurrent source 36 through contact member 40brush 41, wire 116, contacts112, lead 115 to bus 139 through winding 75, contactsl 89, spring member68, spring member 63, through wire 91 back to the B side of the directcurrent source 36. The direct current path thus established extendsthrough conductor 140 and through winding 141 on relay 136, throughconductor 103, returning to the signaling circuit 102. This results inthe closing of armature 142, thus closing contact 143, which ismaintained closed by the energization of the electromagnet 144, whichobtains its energy fromthe circuit established through lead 145,generator 36, lead 146, winding 147, wire 170, the winding on relay 90,leaf spring 64 contact spring 71 to the line 91 to the B side of thedirect currentsource 36. The other side of electromagnetic winding 144connects through armature 142, contact 143, lead 146, electromagneticwinding 147 of relay 137, returning tothe line 79, which connects to theA side of the direct current s ource 36. The reverse motor circuit isthereby established. l

Electromagnetic winding 147 draws armature 1,48 to a position whereContact 149 is closed, thereby closing a circuit through electromagneticwinding 150 and lead 151 through electromagnetic winding 1-52, returningto the point 80 on the line 79, thereby placing winding 150 across thedirect current source 36 and maintaining the armature 148 closed withrespect to contract 149. Electromagnetic windings 147 and 150arefsoproportioned that their conjoint influence is necessary to maintain thearmature 148 in closed position under conditions of shock kvibration towhich the apparatus may be subjected and any weakenfng of one windingwith respect to the other is sufficient to open the contacts after theinitial closing thereof as hereinbefore described. Energization ofelectromagnetic winding 152 is suiicient to attract armature 153,closing contact 154,

' energized condition.

thereby completing the alternating current circuit throughelectromagnetic winding 155, and through line 156 to the point 157 onthe side 122 of the alternating current supply line. The alternatingcurrent is thus supplied through line 158 to the eld windings 34a and34, returning through the brush 99, armature winding 98, brush 97, lead96 and conductor 58 to the opposite side of the alternating currentsupply. The combined inuence of electromagnetic windings 152 and 155 isrequired to maintain relay 153 in closed position under conditions ofshock vibration to which the apparatus may be subjected, and uponfailure of energy in the electromagnetic winding 152 after the initialsettings of the armature in closed position armature 153 will bereleased and the circuit to the driving motor broken. The means which Iprovide for maintaining the relay contacts closed as hereinbeforedescribed are for safety purposes for preventing opening of contactseven under conditions of shock vibration to which the control apparatusmay be subjected. So long as the contact springs 64 and 71 remain closedthe driving motor 30 operates in reverse rotation and carries the disc37 in a clockwise direction, but when breaker 53 approaches theextension 64e on leaf spring 64 and abuts with such extension at 64C,the leaf springs 64 and 71 are spread, thus opening the contacts whichdeenergize the relays 136, 13,7 and 138, bringing the motor 30 to astop. It will be observed that insulation strip 64e abuts contact member72, limiting the movement of the disc 37 by the obstruction of breaker53V with the extension 64e.

In order that every precaution may be taken to open the driving motorcircuit 30 at this point contact strip 50 is arranged to establishconnection with brush 51, which connects through lead 159 to thealternating current source from the line 122 and brush 10, therebyenergizing line 159 through. solenoid winding 70, returning through lead123 to the opposite side of the alternating current line, which I havedesignated at 160. This action draws armature 69, which is carried tothe extension of spring member 64, thereby tending to revolve springmember 64 about the pivot 64a, thereby insuring an actual open circuitbetween springs 64 and 71 even prior to the abutment of breaker 53 withthe extension 64e of spring member 64.

It will be observed that the circuits are now ready to receive a signalimpulse for rotation of the motor in a counter-clockwise direction andthe operation heretofore described may then be repeated. At the end ofsuch repeated operation the disc is restored by operation of thesignaling circuit. It will therefore be seen that any one of the controlcircuits may be energized in successive step by step movement, or thecontrol circuits may be energized by the transmission of signalingenergy over a time interval sufficient to move disc 37 in acounter-clockwise direction over the entire range of contact members 1,2, 3, 4, 5, 6, 7, 8, etc. It will be understood that any number ofbrushes may be added to the disc system for controlling independentcircuits on the landing eld. In the reversal process the circuits whichhave been set by the counter-clockwise movement of disk 37 aresuccessively restored to their de- It will be understood that the disc37 is moved in a clockwise direction in one step and not successivelystep by step, and by virtue of the restored action, the several cir- 1cuits on the landing eld which have been energized are rapidly restoredto their normal deenergized condition.

In Fig. 2 I have shown in skeletonized form the direct current powercircuit where the motor is initially at rest and the discs 37 and 38have not been moved. The direct current supply 36 is shown furnishingenergy from the A terminal of the generator through the tongue 63,contact 63, contact 63, 75, conductor 88, contacts 86, relay Winding 84,relay winding 82, returning through lead 61-79 to the B side of thegenerator. completed when the keying circuit at 102 is closed. Byclosing the circuit 102 relay 85 is operated, the armature moving to aposition wherein the contacts are closed at 86 for initiating movementof the driving motor. The motor revolves to the iirst position shown inFig. 3, which maintains the A. C. motor circuit closed and prepares thedirect current circuit by moving strip 40 into Contact with brush 41,and moving contacts 1c into contact with brush 43, completing thecircuit through conductor 118, solenoid Winding 114, conductor 119.Contacts l are closed at 78 by virtue of the fact that the directcurrent power circuit has been closed as shown in Fig. 3 throughconductor 120, back to the A side of the direct current source 36.solenoid 114 is not energized until contacts at 112 are closed, whichcontacts are maintained open in the position or the circuit shown inFig. 3 by energization of relay winding 109 which is energized so longas keying circuit 102 is closed. However, when the keying circuit 102 isopened winding 109 is no longer energized and contacts 112 closed by thedeenergization of solenoid 109. The closed position of contacts 112 hasbeen shown in Fig. 4, which results in the energization of winding 114and the closing of contacts 113.

The closing of contacts 113 has been shown more clearly in Fig. 5 wherethe trip circuit is closed by the contacting of brush 47 with contactla, thus energizing solenoid 66 and insuring the opening of contacts 68,after each successive step in the movement of the discs 37 and 38. Thisoperation insures the opening of the motor circuit after each successiveoperation or the completion of each selection or control of individualcircuits. However, if the signaling keying circuit 102 is held closedcontinuously the trip circuit Will not operate and the discs 37 and 38move continuously until mechanical breaker 52 strikes the extremity 63eof the main relay contacts. Thel discs stop by reason of the opencircuits at contacts 68. As the contact opens at 68 the apparatus isfree to receive the next control sigF nal, which signal may step thediscs 37 and 38 counter-clockwise, or if the discs have reached thelimit of their movement the succeeding signal may reverse the directionof movement of the discs.

The arrangement of the circuits at the limit of counter-clockwisemovement of the discs 37 and 38 has been shown in Fig. 6, where themechanical breaker 52 has closed the contacts between spring member 63and contact strip 67. The contact is closed between spring member 63hand contact 72, which completes the circuit through resistance R to therelay windings 93, leading through conductor 120 to the B side of thedirect current source 36, thereby insuring the movement of relayarmature 76 into an upward position, opening contacts at 78 and closingthe contacts at 77. In this particular circuit The circuit justdescribed is It will be understood that col l trol of armature 69.

diagram I have not shown the complete circuit from contact 77 but mayprovide other control circuits adapted to be actuated by the closingofthe contact 77. The reverse circuitis closed to the Ymotor systemthrough relay 136. The closing of this control circuit can only bebrought about by the actuation of the keying circuit 102, and thecircuit may be traced from the keying circuit 102 through relay winding141, brush 45,

contact member 8c, strip 40, brush 41 to contacts 112, which arenormally closed when keying circuit 102 is open. When the keying circuit102 is closed solenoid 126 is energized and contacts 112 are opened,which restores the relays to their normal position and prepares thecircuits for movement of ythe motor in a counterclockwise direction fromthe cycle of movement. In Fig. 7 I have shown the completely reversedposition of the discs 37 and 38, where the discs have been movedcounter-clockwise to restore all of the control circuits to their normalposition. The mechanical breaker 53 contacts with projecting portion 64eof strip 64, opening contacts between 64 and 71, at the same time thatsuch 25' contacts are maintained in open position by energy picked upfrom brush 51 on contact strip 50, resulting in the energizing ofsolenoid winding 70 and the movement of strip 64 under con- The circuitscontrolled by the disc Yare all restored to their original conditionready for repeat operation.

The circuits which I have designated 1, 2, 3, 4, 5, 6, 7 and 8 in Fig. 1lead through a cable from the lreceiving station, as shown in Fig. 8 tothe several control circuits on the landing eld, as illustrated in Fig.8. Antennae 172 and 173 supported by masts 170 and 171 are locatedadjacent the landing eld and connect to the receiving apparatus oppositethe landing iield. The circuits 1, 2, 3, 4, 5, 6, 7 and 8 extend to theequipment on the landing iield.

The conductor 180 of the pair of conductors 122 energized from a sourceof alternating current is common to the several circuits on the landingiield. Circuit 1 extends tothe lights 181 on the landing field whichserve to outline the four directions of the compass, the number of thelanding field, the geographical location ofthe l landing field and otherdata which is to be imparted to the pilot of the approaching aircraft.By closing the control circuit numbered 1 a circuit is completed fromthe alternating current source through the lamps 181 which areilluminated tol advise the pilot of the geographical location over whichhe may be iiying and 'the direction of Hight or bearing of the landingeld. Circuit 2 extends through the lights 182 which designate the limitsof the landing field, which lights are illuminated when the controlsignal necessary to actuate control circuit 2 is received. In order toenergize circuit 2 the disc 37 must be advanced to a position wherestrip 50 bridges contact 2. Circuit 3 extends to the lights 183 whichdesignate the landing zone on the landing eld.

Circuit 4 extends to the flood lights 184 which are carried by therevolving carriers 133 for sweeping the landing field with light. Inorder that the angular position of the ood lights 184 may be properlyregulated, a control circuit 5 is provided on the driving motors 132,enabling these motors to revolve the tables 133 to a position which willpermit the required illumination of the iield for a safe landing.

To advise the pilot of the positive opening of the circuit to thedriving motors 132, an indicator lamp of distinctive color may beenergized by control circuit 6 by the transmission of a control signalwhich will shift disc 37 to contact 6.

Additional control circuits V7 and 8 may be provided on the landingfield, and other control' circuits may be established for performingother functions under control of additional contacts on the movement ofdisc 37.

To recapitulate the sequence of operation employed in the controlapparatus of my invention, Figs. 2, 3, 4, 5, 6 and 7 maybe considered asshowing the successive steps in the operation of the control circuits;Fig. 2 shows the application of the power to the motor control circuit.Direct current is employed to condition the control circuit whereby thedriving motor is energized from the alternating current supply circuitand operates to shift the discs 37 and 38 to the first control positionwhen key 102 is momentarily depressed. As soon as key 102 is released,the motor circuit is de-energized and the apparatus is brought to rest.opened Winding 109 is de-energized and contacts 112 are closed thusenergizing winding 114 and closing contacts 113 as illustrated in Fig.4. The trip circuit is closed by the contacting of brush 47 with contactla thus energizing solenoid 66 and opening the contact 68 which insuresthe cutting oi of the motor circuit after each successive operation orcompletion of each selection or control of individual circuits. Thislatter operation is pictured in Fig. 5. It will of course be understoodthat if the signaling key 102 is held closed continuously the tripcircuit will not operate and the discs 37 and 38 will move continuouslyuntil mechanical breaker 52 strikes the extremity 63e of the main relaycontacts. The condition existing at the limit of the counterclockwisemovement of discs 37 and 38 is shown in Fig. 6 where the mechanicalbreaker 52 has closed the contacts between the spring member 63 andcontact strip 67. The closing of this circuit operates to enable themotor to be energized in a clockwise direction for restoring the contactsystem carried by discs 37 and 38 to the original position which isshown in Fig. 7. The complete cycle is then ready for repetition.Depending upon the time period of closing the, keying circuit 102, thecontrol circuits may be selected progressively or all of the circuitsoperated by the continued closing circuit 102. The keying circuit 102 isthe equivalent of a relay circuit operated from the output circuit of aradio receiver which may receive signaling energy from an aircrafttransmitter enabling the pilot to selectively energize desired circuitsat a landing eld. The character of transmitter employed with the systemof my'invention is set forth more fully in my copending applicationSerial No. 390,-

to the apparatus on the landing eld by which thev various devices incircuit with the landing iield are controlled. Circuit 1 as heretoforenoted serves to control lights 181 enabling the pilot to light the lampswhich spell out the identity of the landing field. Circuit 2 controlsthe lights 132 which designate the limits of the landing eld.

Circuit 3 controls the lights 183 which mark the ice icc

landing Zone on the landing field. Circuit 4 controls the flood lights184. Circuit 5 controls the driving motors which operate the floodlights. Circuit 6 controls light 135 for indicating to the pilot thatall circuits have been closed for actuating the apparatus on the landingfield so that a safe landing may be made. The additional controlcircuits '7 and 8 may lead to other parts of the landing field.

I have found the apparatus of my invention practical in its constructionand successful in its operation for informing pilots of aircraft of allconditions of the landing field during fog or darkness. The apparatus isrelatively inexpensive and when installed in an aircraft landing systeminsures safety in air navigation by providing means readily operableunder control of the pilot for indicating landing conditions preparatoryto the landing of the aircraft.

While I have described my invention in certain preferred embodiments, Idesire that it be understood that modifications may be made and that nolimitations upon my invention are intended other than are imposed by thescope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. An electrical control system comprising a reversible drive, anactuating circuit connected with said reversible drive, a contact systemcontrolled by said drive, a plurality of control circuits individuallyand successively operable by move-- ment of said contact systemstep-by-step in a counter-clockwise direction to selected positions, aset of relays for controlling the actuating circuit of said reversibledrive for effecting counterclockwise movement of said drive, a separateset of relays for controlling the actuating circuit of said reversibledrive for effecting the clockwise uninterrupted movement of said contactsystem, and means operative upon the limits of movement of said contactsystem for rendering said rst mentioned set of relays ineffective, andrendering said second mentioned set of relays effective for restoringsaid contact system to the original position thereof.

2. An electrical control system comprising a reversible drive, anactuating circuit connected with said reversible drive, a contact systemcontrolled by said drive, a plurality of control circuits individuallyand successively operable by movement of said contact system to selectedpositions, a set of relays for controlling the actuating circuit of saidreversible drive for effecting counterclockwise step-by-step movement ofsaid drive, a separate set of relays for controlling the actuattingcircuit of said reversible drive for effecting the clockwise continuousmovement of said contact system, and electromagnetic means operativeupon the limits of movement of said contact system for rendering saidfirst mentioned set of relays ineffective, and rendering said secondmentioned set of relays effective for restoring said contact system tothe original position thereof.

3. An electrical control system comprising a reversible drive, anactuating circuit for said reversible drive, a contact system controlledby said 1 drive, a plurality of control circuits individually andsuccessively operable by movement of said contact system, a set ofrelays for controlling the actuating circuit of said reversible drivefor effecting counter-clockwise step-by-step progressive movement ofsaid drive to selected positions, a separate set of relays forcontrolling the actuating circuit of said reversible drive for effectingclockwise continuous movement of said contact system, and compositemechanical and electro- 1 magnetic means operative upon the limits ofmovement of said contact system for rendering said first mentioned setof relays ineffective, and rendering said second mentioned set of relayseffective for restoring said contact system to the 1 original positionthereof.

SEARCY L. MCFADIN.

pri

